Heating elements are generally used for physical equipment, technical equipment, heating devices, process technology installations, etc. The operating temperature of these elements frequently increases in an impermissible manner when there is a change in the physical parameters, such as heat storage capacity, conductivity and/or cooling rate of the equipment.
Likewise, the ability of the equipment to function can be impaired, if the intended surface temperature of the heating device is not reached.
With heating apparatuses, particularly radiators, the danger of overheating exists, so that there is danger of fire if the heat-transfer medium, generally water, is present in an insufficient amount in the equipment.